Refrigerating system



June 3, 1930. E. A. WEAVER REFRIGERATING v SYSTEM Filed Aug. 2s, 1924 llllll .||L

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..v I v 4 y 4 lns Patented June 3, 193() 'i y UNITEnf STATES.

PATENT OFFICE EASTMANA. WEA-VER, or EEooxIvLrNE; MASSACHUSETTS, ASSIGNOEQEY MESNE As- SreNMENTaToIsTAToR REEBIGEEATIVON, INC., A CORPORATION or DELAWARE REERIGEBATING SYSTEM Appiicauon med August 2a, 1924. serial No. 733,699. j i A,

'This invention relates .to a refrigerating system of the vtype having an aspirator for impelling refrigerant vapor from a cooler to a condenser' and employing a propellantfluid.;A 5 different from the refrigerant Huid, and more"- particularlytoa system having a boiler for generating the propellant vapor, avapor duct leading from the boiler to the aspirator, a liquid duct leading from the condenser to the 10 boiler throughwhioh the propellant 'liquid returns to the boiler and in which a head vof the propellant liquid balances the difference in pressure between the boiler and condenser.

It yhas been recognized for many years that systems of this type offer `unique possibilities, especially for small household installations, since they need no valves or moving mechanical parts and may be permanently sealed and will operate automatically. However, while yoffering great possibilities theoretically, no one has been able, so far as I am aware, to make a practical refrigeratingsystem typeq Objects ofthe present invention are. to overcome Vthe practicalv difculties which have heretofore prevented vthe development Y* of a successful system of the aforesaid ,type and so to determine the many interrelatedfactors which are involved ina system of this the propellant fluid on the intake and, outlet sides of the aspirator. If the temperature difference ofthe ratio of pressures is low the efficiency is low and if thepressure on the inlet side is excessive it is impractical to construct the apparatus to operate satisfactorily under high pressure. I'have discovered that efficiency can be attained Without employing h1 pe lant liquid having a boiling point higher C.) at atmospheric pressure, and employing `a refrigerant havingavapor pressure below .100 mm.

Another factor which I have found to be .5 0 very important is the shockl loss inthe aspiraof this kind that the apparatus is simple, compact',r

'gh pressure apparatus by employing a prothan 100 C. (and preferably higher than 300 (and preferably below 15 mm.) at

tor ,resulting from the impact'of the molecules of propellant vapor against the molecules of refrigerant vapor; and I have disycovered that this factor can be kept within Apracticable limits byvemploying a propellant vapor whose molecular weight is at least approximately four times the molecular Weight` of the-refrigerant vapor.

A third factor which is most important,

vparticularly in household installations, is the two and preferably whose density is at least approximately vfourteen times the density of the refrigerant liquid.

' The two liquids should also be immiscible so that they may be readily separated and returned to the boiler and cooler respectively after their vapors commingle in the aspirator and arecondensed. f I

The liquids which best fulfill all these conditions, so far as I am atl present aware, are

mercury and water. When using mercury as the prriipellant and water as the refrigerant 'good e ciency can be attained with a boiler pressure as low as one atmosphere. Other combinations of liquids (e. gl mercury and alcohol) meet a part or all of the above condit-ions and the invention is therefore not limited, except as recited in the appended claims, to the use of mercury and water.

In the accompanying illustration of a concrete form of apparatus for practising the invention- Fig7 1 is a diagrammatic Side view, partly in section; and y' Figs. 2 and 3 are enlarged sections on lines 2%2 and 3-.3 ofFig. 1.

' Referring to the drawings the cooler may comprise a seriesof coils lrmounted in transverse plates 2 to facilitate the transmission of heat from the region to be cooled, for example the interior ofa refrigerator. Thev condenser is preferably mounted above thecoolerv so that the propellant and refrigerant fluids may be Condensed therein and returned respectively by gravity to the boiler and the cooler.

In this instance the condenser comprises parallel) tubes 4 and 5, preferably formed in one piece. A casing 7 surrounds the lower tube 4 for a portion of its length; and integral websv8 extend between the tube 4 and casln 7to facilitate the transmission of heat from t e tube to atmosphere. The upper tube is-provided with a similar casing 9, which is' integral with the casing 7 and extends substantially the entire length ofthe tube, and webs 10 integrally connect the tube 5 and casing 9 to afford a greater radiation. The/inlet end of thetube .4 is bent slightly upwardly as sho n extends into thelowermost portion of end 11. The tube -22 extends outwardl and downwardly and terminates at `its lower end in coils 13 which are located vwithin the vaporizer v14. The vaporizer 14 may .be of any suitable type and in this instance comprises a hous- /ing v15 having a burner 16,`which is supplied with a gaseous-fuel from the inlet '17, and a flue 17 surrounding ducts 12 and 22. 4

The arrangement of the condenser shown inthe drawing permits the propellant liquid to be returned tothe boiler hot, while the refrigerant liquid is returned to the cooler near room temperature. The mixed` vapors entering lthe condenser first traverse the upward slanting hot portion 4 in which most of the propellant fluid is condensed and flows to the hot outlet 22, and the remaining vapors then traverse the .cooler downward-sloping portion 5 in which most'- of the, refrigerant vapor is condensed and flows to the cooler outl r let25. While the two condensin tubes are shown as air-cooled, one or bot may be cooled in any suitable manner as by a water jacket: indeed, the condenser or'condensers ma be of any suitable construction. u

he propellant liquid is vaporized in the vaporizer 14 andthe vapor passes through the tube 12 and aspirator 18 consisting of a restricted orifice 19 and passage 19' tapering outwardly from the orifice so that the vapor as it passes therethrough expands approximately adiabatically with a large-drop rassure and great increase in velocity. he orifice and passage are preferably so ydesigned that the pressure at the outlet of `the passage is a proximately equal to the pressure of the re rigerant vapor corresponding to the temperature atwhich it is designed to maintain the refrigerant liquid in the' cooler. Where water is the refrigerant and 'a temperature of freezing is desired in the cooler, the pressurev of the water vapor cori responfdin tewater at 0 C. is a proximately V4.6 mm.4 tween-tbe outlet o? the passage and the restriction 21, the refrigerant vapor is entrained in/ the stream of the propellant vapor. The molecules of propellant' vapor give some oftheir ener .to the molecules of refrigerant Vapor, Where. Y the averagetmnsat 11 and a smaller tube 22- pressure corresponding to the vapor pressure of the refrigerantI liquid in the condenser tube 5. In the case of water the backy ressure willvary between 30 and 60 mm., epending on the room' temperature and condenser etilciency. The' condensed v propellant flows through aportion of the tube 4, due to the inclinatlon of the latter, into the .feed pipe 22 which extends downwardly parallel to the tube 12 and terminates in coils 23, the-lower end of pipe 22 being integrally connected to the inlet end of the coils 13. The propellant liquid inthe pipe 22 serves as 'a static feed co umn for the vaporizer and the weight of the liquid in this pipe is sufficient to 'balance the pressure of the vapor in pipe 12 and coils 13.

The condensed water flows by gravity through the tube 5, due to the inclination of the latter, to a collecting -ch/arnber -24 into ,which extends an outlet pipe 25 above the bottom of the chamber. The water overflows into the pipe 25 which-is cnnected at its opposite end to an intermediate coil of the coolsu stantially U-shaped at itslower end inl which there is a column 26 of relatively dense liquid, preferably me cury, which serves to maintain a lower presure in the cooler 1 than inthe condenser. The water flowing through the pipe 25 may have a vapor pressure of from 30 to 60 mm. and as it bubbles through the mercur column 26 it expands into the cooler in w ich the pressure is lower causing evaporation to take place.

The urpose of the collecting chamber is to cause t e refrigerant liquid, which is at relatively low temperature, to keep the walls of the passage around the restrlction 21 cool enough tol condense some of the relatively inert propellant vapor in contact therewith, which otherwise would have uselessly increased the volume of vapor to be compressed. The refrigerant' pressures' given v above are merely by way of example and if it is desired to vary `the temperature within the cooler 1 the rate of vaporization in the va' porizer may be varied which will result in varying the pressure of the vapors so that the rate of heat absorption in the cooler will accordingly increase orA diminish. As water lfreezes at 4.6 mln'.v it is desirable that the vapor pressure in the cooler be maintained in aplproximately that region in` order toy obtain the est refrigerating e ect.- A slight amount of propellant fluid may pass into the cooler 1 and due to its relatively` great liquid density will flow into the lower coil from which it is conwhich is connected ytoo-the ipe 22 atits lower end. A trap 28 filled wit propellant liquid preventsv refrigerant v from flowing to the` boiler. f A v Y It may be desirable under some conditions tolower the freezing point of the refrigerant 1o preferably one which with the refrigerant will produce a constant boiling mixture at a given pressure e. g. 4 mm., may be added thereto. l

From the foregoing it will be evident that the essence of the present invention, in a broad aspect, is the relation between the characteristics of the propellant and refrigerant fluids employed. In another broadaspect the invention involves the use of propellant and refrigerant circuits (13 -2-,1819-19-21-11,-4 22-33 o and 20-21-11-4-5-24-25-26- l) having a part "in common (21-11-4) characterized by means for automatically returning` the propellant and refrigerant liquids from any part of the system to the vaporizer and cooler respectively. In the illustrated embodiment, for example, if mercury finds its way into the refrigerant condenser 5 or cooler l or other part of the refrigerant circuit, due to tipping or upturning the system or to its being carried to the refrigerant circuit by the refrigerant stream or in any other Way, it is automatically returned to the vaporizer by the normal operation of the system. That is, mercury may vflow from the refrigerant condenserto the cooler through pipe 25 and trap 26 and vthence from the coolerto the vaporizer through pipe 27 and trap 28. Thus 40 none of the propellant can'be rendered useless by lodgment in some part of the refrigerant circuit vother than said common part;

and obviously the refrigerant can not becomepermanently lodged in any part of the propellant circuit. While limited amounts of propellant are intentionally trapped at 26 and 28, any excess tending to accumulate in these traps runs over, to the cooler from trap 26 and to the vaporizer from trap 28.

the preferred way vof' obtaining this unique result is to employ pressure balancing means such as the mercury columns in ducts 22 and 27 and traps 2G and 28, which serve the double function of balancing ,the pressures and permitting the automatic return of stray propellant.

It will also be evident that the novel relationship of parts (both fluid and solid) makes it possible to employ pressures, the maximum of which may be of the order of an atmosphere, a pressure which is free from danger of explosion.

I claim:

1. A refrigerating system of the type em- From the foregoingit will be evident that` -por from the vaporizer to the propellant condenser, a duct .for conducting refrigerant liquid from the refrigerant condenser to the cooler, means for maintaining a lower pressure in the cooler than in the refrigerant condenser, an aspirator in said first duct, and

.a duct leading from the cooler to said aspirator, so that the propellant vapor flowing from the vaporizer to the propellant condenser impelsrefrigerant vapor from the cooler to the refrigerant condenser, lthe propellant liquid having a relatively high boiling point and the refrigerant liquid having a relatively low boiling point whereby a high temperature drop can be obtained between the vaporizer and condensing means without employing high pressure in thevaporizer.

2. A refrigerating systemof the type employing a refrigerant flui'd'and a heavier propellant fluid, comprising a propellant vaporizer, a propellant condenser, a vapor duct leading from said vaporizer to said condenser, a ductleading` from said condenser back to said vaporizer for returning the condensed frigerant condenser by virtue of the weight ofV the liquid in the trap, an aspirator in said first duct, and a vapor duct leading from the cooler to said aspirator, whereby the propellant vapor impels the refrigerant vapor fromA the. cooler to the propellant condenser, the propellant vapor being then condensed for return to the vaporizer and the refrigerant vapor passing on to the refrigerant condenser where it is condensed and delivered to the cooler.

3. A refrigerating system of the type employing mercury as a propellant fluid and a lighter refrigerant-fluid, comprising a mercury vaporizer, a propellant condenser inwhicli propellant vapor is condensed at a suitable temperature, a refrigerant condenser in which refrigerant vapor is condensed at a lower temperature, a cooler, a duct for conducting mercury vapor from the vaporizer to the propellant condenser, a duct for conducting refrigerant fluid from the refrigerant condenser to the cooler, an aspirator in said first duct, and a duet leading from the cooler to said aspirator, whereby the mercury vapor flowing from the vaporizer to the propellant denser -in whic condenser impels refrigerant vapor from the cooler to the refrigerant condenser.

4. A refrigerating system of the type employing water as t e refri erant fluid and mercury as the propellant uid, comprising a mercury vaporizer, a propellant condenser in which propellant vapor is condensed at a suitable templerature, a refrigerant conrefrigerant vapor iscondensed at a lower temperature, a cooler, a duct for conducting mercury vapor from the vaporizer to the propellant condenser, a duct for conducting water from the refrigerant condenser to the cooler, means for maintaining a low pressure in the cooler, an aspirator in said first duct, and `a duct leading from the cooler to the said aspirator, whereby mercury vapor flowing from the vaporizer to the propellant condenser impels water vaporr from the cooler to the propellant condenser and thence to the refrigerant condenser.

5. -A refrigerating system of the type employing different refrigerant and propellant fluids, comprising a propellant vaporizer, a

ropellant condenser, a vapor duct leading from saidvaporizer to said condenser, a duct leading from said condenser back to said vaporizer for returning condensed propellant back to the vaporizer, a refri erant condenser, a cooler, a duct leadin frigerant condenser to -the coo er, an aspirator -in said first duct, a vapor duct leading from the cooler to the aspirator, whereby the propellant vapor impels the refrigerant vapor from the cooler to the refrigerant condenser, the propellant vapor being first condensedin the propellant condenser and returned to the vaporizer, and means in said last duct leading from the refrigerant condenser to the cooler' for maintaining a lower pressure in the cooler than in the refrigerant condenser. s

6. In\a refrigerating system having a cooler containing refrigerant liquid, the method which comprises exhausting the cooler by entraining vapor from the cooler in a stream of the vapor of a liquid havina boiling point different from that of the re rigerant liquid,

` and condensing the vapors in different locations respectively for separate recirculation.

7. Ina refrigerating system having a duct for conducting refrigerant vap or from a cooler to a dissilator, the method which com prises prope 'ng er to a dissipator, the method which comthe vapor fromthe cooler' to the Vdissipator by entraining va or from the cooler inthe vapor of a ropel ant havprises propelling the vapor from the cooler to the dissipator by entraining vapor from the cooler in a stream 0f the vapor of a liquid having a higher boiling point than the refrigerant and being substantially immiscible therewith, condensmg the propellent ,vapor- Abefore it reaches the dissipator and shunting it from said duct, revaporizing the condensed propellent vapor and again using it for aspiration as aforesaid.

9. In the art of refri eration by circulating a refrigerant flui with a propellent fluid, the method which comprises passing a gaseous propellant of comparatively high molecular weight from a region of substantial pressure to a region of lower pressure so that the propellent stream acquires considerable kinetic energy, and entraining in said propellent stream the vapor of a refrigerant having a vapor pressure of the order of a few percent of any atmosphere, and a molecular weight less than one-quarter that of the propellant whereby the pressures in said first region need not be hi h.

10. In the art of re rigeration by circulat- I ing a refrigerant yfluid with a propellent fluid, the method which comprises assihg a gaseous prepellant from a region o substantial pressure to a region of lower pressure so that the propellent stream acquires considerable kinetic energy, and entraining in said ro ellent stream theva or of a refrigerant avmg a molecular w1ghtf less than oneeighth of that of the propellant, whereby the energyL loss due to impact of the` propellent molecules with the refrigerant molecules is comparatively low.

11. In the art of refrigerationv by circulating a refrigerant fluid with a propellent fluid, the method which comprises passing a gaseous propellant of comparatively high molecular weight from Ja. re loof substantial temperature to a region o lower temperature, introducing into said propellent stream the vapor of a refrigerant having a vapor pressure of the order of a few percent of an atmosphere at 0 C. and a molecular weight less than one-eighththat of the propellant whereby the pressure in said first region need not be high. I

12. A refrigerating' system comprisingva vaporizer conta-ming a propellent liquid,v a

cooler containing refrigerant liquid, said prolll effect condensation of refrigerant, means for balancing the vapor pressure in the vaporizer,

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and for returning condensed propellant thereto from the duct, and a duct for returning condensed refrigerant from the second condenser portion to the cooler. Y. 13. A refrigerating system comprisingy a. propellent vaporizer, a cooler, 'propellent and refrigerant liquids of different boiling-points in said vaporizer and cooler, respectively, an aspirator nozzle adapted to receive propellant and to discharge the same into va passage connected with the Acooler whereby vapor from the cooler may be aspirated by a stream of propellent vapor, said passage being con- Vtinued to provide successive condenser sections adapted to effecty condensation of the propellant and refrigerant respectively, ducts connected to substantially the lowest parts of each of the condenser sections', one of `said ducts being connected to the vaporizer to return condensed propellant. thereto and the other of said ducts being connected to' the cooler to return condensed-refrigerant thereto, and means associated with the first-named duct to balance the difference in pressure between the corresponding condenser section and the vaporizer and yet to permit passage of liquid refrigerant to the same. e

14. vA refrigerating I system comprising a propellent'vaporizer, a cooler,.propellent and refrigerant liquids of different boiling points in said vaporizer and cooler, respectively, an

aspirator nozzle adapted to receive propellant and to discharge the same intov a passage con- -nected with the cooler whereby vapor from the cooler may beaspirated by a stream of propellent vapor, said passage being con? tinned to provide successive condenser portions to effect the 'substantially separate condensation of the propellant and refrigerant, drains connected to substantially the lowest parts of each of the condenser sections, one of said drains being connected to the vaporizer to return condensed propellant `thereto. and the other of said drains being connected to the cooler to return condensed refrigerant thereto, said drains being arranged to hold liquid columns to permit differences in vapor pressure between the respective condenser sections-and the vaporizer and cooler and yet to permit passage of condensed vapor to the vaporizer and cooler respectively.

15.. A refrigerating system comprising a vaporizer containing a comparatively heavy propellent liquid, a cooler containing a comparatively light liquid, said liquids having different boiling points, means whereby va.-

porized refrigerant may be drawn from the cooler and entrained in a stream of vaporized propellant, a duct to receive the stream of mixed vapors, said duct lncluding successive W condenser sections, one of said sections having a drain to return condensed refrigerant to the cooler, the 'other of saidsectionshaving a 'y c drain `to `returnthe condensed propellant to -the.vaporizer, said last-named drain being arranged tocontain a column. ofthe heavy propellentv liquid "to balance the vaporizer` pressure. v 16. A refrigerating system comprising a vaporizer containing mercury, a cooler containing a refrigerant liquid substantially/immiscible with mercury an aspirator nozzle adapted toreceive vapori'zed mercury'from.

the vaporlzer, means wherby refrigerant vafpor may be aspirated by the propellent stream emitted from vthe nozzle, a passage adjoining the outlet of the aspirator which isadapted to receive the stream of mixed mercury and refrigerant vapors, a. continuation ofl said passage being provided with cooling means to effect condensation of-mercury and a second condenser portion forming a continuation of said passage to effect condensation of the refrigerant, and means for 'returning liquid mercury from the first condenser portion to 'the vaporizer.

17 A refrigerating systenrof the type using different propellent andl refrigerant liquids in propellent and refrigerant circuits havinga part in common, comprising acooler containing refrigerant liquid in the refrigerant circuit, means including a vaporizer in the propellent circuit yfor circulating propellant therearound with the propellant in vapor form when it enters said common'part, means for causing the propellent vapor lin said com' lnonpart to circulate refrigerant vapor from the cooler, means in saitl circuits for condensing the propellent andv refrigerant vapors for return to the vaporizer-and cooler respectively, and means for automatically returning the propellent and refrigerant liquids from any part of the system to the vaporizer and cooler respectively.

18. A refrigerating system of the type using different propellent and refrigerant liquids, in propellent and refrigerant circuits having a part 1n common, comprising a cooler containing refrigerant liquid in the refrigerant circuit, means including a vaporizer in the propellent circuit, for circulating propellant therearound with propellant in vapor vform when it enters said common part, means for causing the propellent vapor in said common part to circulate refrigerant-vapor from thecooler, and means in said circuits for condensing and returning the propellent and refrigerant to the vaporizer and cooler respectively, including means for automatically returning to the vaporizer propellant'liquid which strays to the cooler. 19. A- refrigerating system of the type using different propellent and refrigerant liquids, comprising propellant and refrigern .the propellent circuit forcirculating propellant therearound with the propellant in vapor form wheny it enters said common part, means for causing the propellent vapor in said common part to circulate refrigerant `vapor from the cooler, means in said circuits for condensing and returning the propellent and refrigerant to the vaporizer and cooler respectively, and pressure balancing means associated with said circuits permitting theautomatiq return to the vaporizer of vpropellent which strays to any part of the refrigerant circuit, said last means maintaining different pressures in the vaporizer, condensing means and cooler respectively.

20. A refrigerating system of the type using different propellent and refrigerant liquids in propellent and refrigerant circuits having a part in common, comprising a cooler containing refrigerant li uid in the refrigerant circuit, means inclu 'ng a vaporizer in the propellent circuit for., circulating propellant therearound with the propellantin vapor formwhen it enters said common pa-rt, means for causing the propellent vapor in said common part to circulate refrigerant vapor from the cooler, means in said circuits for condensing the propellant and refrigerant for return to the vaporizer and cooler respectively, and

pressure balancing means associated with said circuits permitting the automatic return to the vaporizer' ofpropellant which strays to` the refrigerant circuit, said last means including a column of propellent liquid in a duct through which propellant flows from the cooler to the vaporizer.

21. A refrigerating system of tlie type using different propellent and refrigerant liquids,V propellent and refrigerant circuits l having a part in common, a cooler containing refrigerant liquid in the refrigerant circuit,

means including a vaporizer in the propellent circuit for circulating, propellant therearound with the propellant in vapor form when it enters sai common part, means for causing the propellent vapor in said common part to circulate refrigerant vapor from the cooler,

' means in said circuits for condensing the propellant and refrigerant4 for return to the vaporizer andcooler respectively, and' pressure balancing means in the system permitting the automatic'return to the vaporizer of propellant which strays to the refrigerant circuit, said last means including a trap in the path of refrigerant liquid flowingV from the condensing means to the cooler.

22. A refrigerating system of the `type usin pro ellent and refrigerant liquidswhic are iminiscible, the former being heavier than the latter, in propellent and refrigerant circuits having a part in common, comrising a cooler containing refrigerant liquid in the refrigerant circuit, means including a vaporizer in the propellent circuit for circulating propellant therearound with the prorefrigerant va or from the cooler, means insaid circuits or condensing the propellant, 7o

and refrigerant for return to the vaporizer and cooler respectively, and pressure balancing means associated with said circuits permitting the automatic return to the vaporizer of propellant which strays to the refrigerant circuit, said last means includin a tra containing propellant in a duct throug whic propellant Hows from the cooler to the vaporizer.

23. A refrigerating system of the type using propellent and refrigerant liquids whichare immiscible, the former being heavier than the latter, comprising propellent and refrigerant circuits having a part in common, a cooler containing refrigerant liquid in the refrigerant circuit, means including a varizer in the propellent circuit for circulating propellent therearound with the propellent in vapor form when it enters said co'mmon part, means for causing the propellent vapor in said common art to circulate refrigerant vapor from t e cooler, means in vsaid circuits for condensing the propellent and refrigerant for return to the va orizer and cooler res ectively, and pressure balancing means in t e system permitting the automatic return to the vaporizer of propellent which strays to the refrigerant circuit, said last means including a tra containing the heavier propellant in a duct eading Ifrom the condensing means to the cooler.

24. A refrigerating system of the type using different propellent and refrigerant liquids, comprising propellent and refrigerant circuit having a part in common, a coolerv in the refrigerant circuit containing refri tle' entv pressures in the vaporizer, condensing means and cooler respectively, while confining the highest of said pressures to the order of an atmosphere. l

25. A refrigerating system comprising mercury and water as propellent and refrigerantliquids respectiv ,mercury and water circuitshaving a part in. common, l,a cooler containing water in the'refrigerant circuit,

means including a vaporizer in the mercury f circuit for circulating mercury therearound with 'the mercury in vapor form when it env ters said common part, means for causing the propellent vapor in said common part to cir- -prises propelling the vapor of a refrigerant having'a boiling point much lo.Wer than that.

of mercury from the cooler to the dissipator by entraining vapor from the cooler in a stream of mercury vapor and condensing the latter before it. reaches the dissipator.

27. In a refrigerating 'system having a duct for conductin cooler to a diss1pator,the metho which com`- prises propelling water vapor from the cooler refrigerant va or from a 31. A refrigerating system comprising a cooler, an aspirator nozzle, a duct for .conducting refrlgerant vapor from said cooler to said nozzle, means whereby aspirated propellent vapor may draw said refri rantv through said duct and become mix with said refrigerant vapor, and two condensers situated at different' levels and connected with the outlet of said nozzle and said duct, the heavierl of the two vapors collecting and condensing in the lower condenser andthe lighter vapor separating from the heavierv vvapor and condensing in the upper conden- Ser.

Signed b me at Boston, Massachusetts, this elevent day of August, 1924.

EASTMAN A. WEAVER.

to the dissipator by entrain'ing the water vapor from the cooler in astream of mercury Vapor and condensing the- .latter 'before it reaches the dissipator.v` s

28. -In a refrigerating system having refrigerant and propellant circuits with a art in common, the art of refrigeration which comprises employing'aheavy propellantof point and a lighter relatively ,volatile refrigerant which 1s substantially high boiling immiscible with the propellant, vaporizing the propellant in onepart of its circuit, entrainin refrigerant vapor from a liquid bod o refrigerant in a stream of the vaporz'e propellant, subjecting the resulting stream of-mixed vapors to a cooling effect to.

condense the propellant, subsequently condensing the refrigerant, returning the condensed refrigerant to the cooler, directing the condensed propellant to the top of a liquid column, feeding propellant from the lower end of the same to the region of propellant yaporziation, and thus continuously circulating the li uids while de ending upon their different weights. and thelr immiscibility to keep them substantially separated except in the common part of the circuits.

29. The art of refrigeration which com' prises vaporizing a refrigerant in the region to be cooled by entraining itin a stream of propellant vapor having a higher weight and a higher condensation point than that of the refrigerant vapor condensing the propellant out of the refrigerant `and subsequently condensing the refrigerant in a separate region.

30. A refrigerating system comprising a cooler, a nozzle, a duct for directing-refrigf erant vapor from saidcooler to said nozzle,

means whereby propellent vapor may draw' said refrigerant through said duct and be-'f come mixed with said refrigerant vapor, a condenser for one of said vapors,and a. second -condenser betweenthe'noz'zle andthe first condenser for the other of said vapors.'

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